In Europe and America, cardiovascular diseases top the list of death causes. Meanwhile, although cerebrovascular diseases such as cerebral apoplexy ranked rather high in death causes in Japan, a tendency for ischemic heart diseases to increase rapidly has recently been seen as the life-style and diet have neared those of Europe and America.
The term "ischemic heart disease" refers to a series of diseases generally caused when the supply of oxygen to the cardiac muscle does not meet the demand of the muscle for oxygen. Representative examples thereof include coronary arteriosclerosis, acute myocardial infarction and stenocardia. Although a nitro drug, calcium antagonist or .beta.-blocker is now used for the treatment of the above diseases, no sufficiently effective drug has been found as yet. Accordingly, the development of a new drug superior to those of the prior art has been expected.